Conventional digital cameras convert an incoming analog image signal to a digital signal and, prior to processing, clamp the digital image signal. The conventional digital camera uses an auto gain controller (AGC) to perform gain control and gamma control based on the clamped signal. Prior to performing gamma control, the conventional system must secure a dynamic range for subsequent signal processing. The conventional system required a larger dynamic range, to perform gain and gamma control, than that needed for subsequent processing. Thus, a high resolution A/D converter is required to output a sufficent number of bits to secure the dynamic range, even though fewer bits are needed for subsequent processing.
In many circumstances, the cost of an overall system increases as the number of bits processed by the A/D converter increases. For instance, some conventional digital cameras use extremely costly high-resolution A/D converters. Thus, less costly components can be used, if the resolution of the A/D converter is decreased. Divergently, in other circumstances, the cost of an overall system decreases as the number of bits processed by the A/D converter increases. Thus, a less costly system is achieved when using a lower resolution A/D converter.